| Message ID | 20240930092000.5385-1-liankun.yang@mediatek.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v1,1/1] drm/mediatek: Add return value check when reading DPCD | expand |
Hi, Liankun: On Mon, 2024-09-30 at 17:17 +0800, Liankun Yang wrote: > Returns the number of bytes transferred (1) on success. > Check the return value to confirm that AUX communication is successful. > > Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver") Fixes: d9e6ea02fc3f ("drm/mediatek: dp: Add MT8195 External DisplayPort support") Regards, CK > > Signed-off-by: Liankun Yang <liankun.yang@mediatek.com> > --- > drivers/gpu/drm/mediatek/mtk_dp.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c > index d8796a904eca..3cab65345d1e 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dp.c > +++ b/drivers/gpu/drm/mediatek/mtk_dp.c > @@ -2018,6 +2018,7 @@ static enum drm_connector_status mtk_dp_bdg_detect(struct drm_bridge *bridge) > enum drm_connector_status ret = connector_status_disconnected; > bool enabled = mtk_dp->enabled; > u8 sink_count = 0; > + size_t value; > > if (!mtk_dp->train_info.cable_plugged_in) > return ret; > @@ -2032,7 +2033,12 @@ static enum drm_connector_status mtk_dp_bdg_detect(struct drm_bridge *bridge) > * function, we just need to check the HPD connection to check > * whether we connect to a sink device. > */ > - drm_dp_dpcd_readb(&mtk_dp->aux, DP_SINK_COUNT, &sink_count); > + value = drm_dp_dpcd_readb(&mtk_dp->aux, DP_SINK_COUNT, &sink_count); > + if (value < 0) { > + drm_err(mtk_dp->drm_dev, "Failed to read DP Sink Count: %zd\n", value); > + return ret; > + } > + > if (DP_GET_SINK_COUNT(sink_count)) > ret = connector_status_connected; >
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c index d8796a904eca..3cab65345d1e 100644 --- a/drivers/gpu/drm/mediatek/mtk_dp.c +++ b/drivers/gpu/drm/mediatek/mtk_dp.c @@ -2018,6 +2018,7 @@ static enum drm_connector_status mtk_dp_bdg_detect(struct drm_bridge *bridge) enum drm_connector_status ret = connector_status_disconnected; bool enabled = mtk_dp->enabled; u8 sink_count = 0; + size_t value; if (!mtk_dp->train_info.cable_plugged_in) return ret; @@ -2032,7 +2033,12 @@ static enum drm_connector_status mtk_dp_bdg_detect(struct drm_bridge *bridge) * function, we just need to check the HPD connection to check * whether we connect to a sink device. */ - drm_dp_dpcd_readb(&mtk_dp->aux, DP_SINK_COUNT, &sink_count); + value = drm_dp_dpcd_readb(&mtk_dp->aux, DP_SINK_COUNT, &sink_count); + if (value < 0) { + drm_err(mtk_dp->drm_dev, "Failed to read DP Sink Count: %zd\n", value); + return ret; + } + if (DP_GET_SINK_COUNT(sink_count)) ret = connector_status_connected;
Returns the number of bytes transferred (1) on success. Check the return value to confirm that AUX communication is successful. Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver") Signed-off-by: Liankun Yang <liankun.yang@mediatek.com> --- drivers/gpu/drm/mediatek/mtk_dp.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)